How do you feel about this article? Help us to provide better content for you.
Thank you! Your feedback has been received.
There was a problem submitting your feedback, please try again later.
What do you think of this article?
This is a tutorial to get you started with using mathematical equations to sketch curves and makes surfaces/solids using them. You will need version 5.0 or newer of DesignSpark Mechanical to access this advanced sketch mode.
Now, let's get started with the tutorial:
Here is the syntax and list of pre-defined functions::
- Parameters include a name and are enclosed in square brackets [L]
- Functions include a function name followed by parenthesis containing any values as arguments
- For example: Sine([t]-[r])
- The table below shows common predefined intrinsic functions included
A full list of mathematical expressions including operators & constants is given in the main help documentation: http://help.spaceclaim.com/dsm/5.0/en/Content/MathematicalExpressions.htm
--
Here's another example of a group of equations to define a symmetric airfoil using the NACA scheme. Give it a try!
This is a NACA 0015 airfoil where the trailing digits '15' means the airfoil has a 15% thickness to chord length ratio ([a] in below equations). Design units were Metric.
Upper surface of airfoil:
x |
([t]) |
y | 5*([a])*((0.2969*Sqrt([t]))-(0.1260*[t])-(0.3516*Pow(([t]),2.0))+(0.2843*Pow(([t]),3.0))-(0.1036*Pow(([t]),4.0))) |
z | 0 |
Interval(t) | Start:0, End:1, Scale:50 |
a | 0.15 |
Lower surface of airfoil:
x |
([t]) |
y | -5*([a])*((0.2969*Sqrt([t]))-(0.1260*[t])-(0.3516*Pow(([t]),2.0))+(0.2843*Pow(([t]),3.0))-(0.1036*Pow(([t]),4.0))) |
z | 0 |
Interval(t) | Start:0, End:1, Scale:50 |
a | 0.15 |
You could change the above equations to build a cambered airfoil, which is used in real world aircraft. Eg. a supercritical NACA 2412 used in A380s. The leading digits '24' indicate the degree of camber.